Gas-engine.



no. 603,000. Pmnud sept. 24, |901.

B. F. STEWART.

GAS ENGINE.

(Application mnd lapt 90, 1000.) (Ilo lodal.) 6 Sheets-Sheet l.

Patnnted Sept. 24, |90l. B. F. STEWART.

GAS ENGINE. (Anuman am m so.

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B. F. STEWART.

GAS ENGINE.

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f www l 66, Z6 I Zwenan My ff lo. 683,080. Patented Supt. 24, |90I. B.F. STEWART.

GAS ENGINE.

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No.683,080. Patented Sept. 24, I90l. B. F. STEWART.

GAS ENGINE.

(Appum med apn so, 1900.)

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No. 683,080. Patented Sept. 24, |90I. B. F. STEWART.

GAS ENGINE.

(Application Mod llpt. 90, 1900.) (In lohl.) 6 Shoah-Sint 6.

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UNITED STATES PATENT OFFICE.

BENJAMIN F. STEWVART, OF CHICAGO, ILLINOIS.

GAS-ENGINE.

SPECIFICATION forming' part Of Letters Patent NO. 683,080, datedSeptember 24, 1901.

Application filed September 20, 1900. Serial No. 30,537. (No modelo T@ZZ whom, if 71mg/ concern:

Be it known that I, BENJAMIN F. STEWART, a citizen of the United States,and a resident of Chicago, countyof Cook, and State of Illinois, haveinvented certain new and useful Improvements in Gas-Engines, of whichthe following is a specification and which are illustrated iu theaccompanying drawings, forming a part thereof.

This invention relates to that type of gasengines in which power isgenerated by the explosion of a charge of gas and air, and moreparticularly to that type of reciprocating engines of this class whichare known as twocycIe engines, in which an explosion occurs at eachrevolution of the shaft.

The objects of the invention are to simplify the construction andincrease the eiciency of engines of this type; and the inventionconsists in the parts and arrangement of parts, as hereinafter fullydescribed and as illustrated in the accompanying drawings, in which-Figure 1 is an elevation of the engine. Fig. 2 is a vertical section onthe line 2 2 of Fig. 1. Fig. 3 isa detail Vertical central section inthe plane of the crank-shaft. Fig. 4 is a detail plan section of theengine. Figs. 5, 6, and' are details of the circuit-breaker of theelectric igniter, Fig. 7 being taken on the line 7 7 of Fig. 5. Fig. 8is a sectional view on the line 8 8 of Fig. 3, some of the parts beingbroken away. Fig. 9 is a detail of the induction-valve. Fig. 10 is asectional detail of one of the parts of the engine. Fig. 11 is atransverse section on the line 11 11 of Fig. 3. Figs. 12 and 13 aredetails of the pitman; and Figs. 14 and 15 are details of theair-induction valve, Fig.'15 being taken on the line 15 15 of Fig. 14.

The engine is shown as being vertical in form, and its trunk comprises acylinder and a base 26, the former superimposed upon the latter, the twobeing joined in the plane of the centerof the crank-shaft. The base 26flares or spreads at the bottom, as shown at 27, and rests upon afloor-plate 28, to which it is securely bolted. The journal-boxes forthe crank-shaft comprise the two parts 29 and 30, the former being castintegrally with the cylinder 25 and the latter with the base 26. Theupper members or caps 29 of the journal-boxes are provided with lugs 3132,

and the lower members of these boxes are provided with correspondinglugs 33 34. These lugs provide means for not only securing the twomembers of the journal-boxes together by means of the bolts 35, but alsofor binding together the two members 25 and 26 of the trunk. Thecrank-shaft is shown at 36 and its wrist-pin at 37. A pair of iiywheels3S and 39 are shown as being mounted upon the two ends of thecrank-shaft. The piston is shown at 40 and is of the trunk type and isconnected with the crankshaft by means of a pitman 42. The pitman ispivotally secured within the body of the piston by means of a pin 43 andis secured to the crank-shaft by means of boxing, consisting of themember 44, cast integrally with the pitman, and a cap 45, completing thecircle of the wrist-pin 37 and secured by means of a U-strap 46, theends of which pass through llugs 47 on the pitman and to which areapplied the nuts 48. The walls of the upper part of the cylinder-that isto say, of the cylinder proper-are chambered, as shownat 49, so as toconstitute the usual water-jacket. An imperforate septum or partition 50is formed across the base 26, near its top, thereby,'with the upperportion of the side walls of the base 26 and the lower portion of theside walls of the cylinder 25, inclosing a com modious chamber 50,within which the crank turns and within which air is compressed by theloutstroke of the piston, ashereinafter more fully described. The sidewalls of this chamber are provided with inwardly-opening spring-closedvalves 5l, covering air-ports 51a, so that at the instroke of the pistonair is drawn into the compression-chamber. The head of the piston 40 isperforated, as shown at 52, so as to permit air compressed below thepiston to pass upwardly into the cylinder or combustion-chamber. Theports 52 are aunularly arranged and are covered by an annular valve 53,which fits loosely within a recess inthe face of the piston, so that itmay freely move transversely to its plane. The recess within which thevalve 53 is housed is covered by an annular plate 54, secured to theface of the piston by suitable screws and having around its aperture anupstanding flange 55. A plurality ofeduction or exhaust ports 56 openthrough the side walls of the IOO cylinder and are so located as to beuncovered during the last portion of the outstroke of the piston. Theseports 56 lead to a duct 57, formed in the wall of the cylinder 25 andalmost encircling it, and a port 58 leads from this duct to theexhaust-pipe 59. The induction-port 60 is through the head of thecylinder and central with reference thereto. Within this port there isfitted a valve-casing 60a, the inner end of which forms the seat 'for aValve 6l,having an outwardly-projecting stem 6l, which passes through astufling-box 62, applied to the outer end of the casing 60a. Thevalve-stem 6la is tubular, and the governor-rod 63, which is fixed inthe piston, passes therethrough, a suitable stuffing-box 64 beingprovided at the outer end of the valve-stem. The governor 63', appliedtothe outer end of the rod 63, may be of any form of that type which iscontrolled by the inertia of a weighted lever. The governor herein shownis not fully described, for the reason that it forms the subject of aconcurrentlypending application. A spiral spring 65, Wound about theouter end of the valve-stem 61, reacts between the cap of thestuffingbox 62 and the cap of the stuffing-box 64 to hold the valve 6lnormally closed. The supply of fuel is contained within a commodiouschamber 66 in the base 26 of the engine. From the chamber-66 there risesa pipe 67, passing through a portion of the exhaustpipe 59, so that aliquid-hydrocarbon fuel may be used, and as it rises in this pipe willbe vaporized by the heat derived from the exhaust, and the Vapor thusgenerated will accumulate in the reservoir 68 at the top of the pipe 67and pass from thence through a tube 69 to an annular chamber 70, aroundthe valve-stem 61a, and within the casing 60a, entering theexplosion-chamber of the engine from this chamber as the valve 6l isunseated. A duct 7l leads from the upper portion of the pressure-chamber50a to the chamber 66, being provided with a suitable check-valve 72, sothat there is at all times a sufficient pressure within the chamber 66,to cause the fuel to rise in the pipe 67. A closed cup 73 is provided atthe upper end of the gas-reservoir 68, within which a small supply offuel may be placed for use in starting the-engine. A port 73a leadsthrough the bottom of the cup 73, and a needle-valve 74 is provided forcontrolling the entry of the fuel from this cup into the pipe 69. Theneedle-valve is formed at the end of the valve 75, controlled by ahandpiece 76, which cuts off communication between the gas-reservoir 68and the tube 69. The lubricant for the engine is placed within thechamber 50, so that the crank of the engine will dip into it andthoroughly agitate it. At the upper end of the pitman 42 there areplaced a pair of deflecting-wings 77,which serve the double purpose ofpreventing the lubricant from being splashed up into the ports 52 and ofguiding the air-currents to the walls of the piston for coolingpurposes.

csaos Ports 78 are formed within the piston-walls` to permit thelubricant to pass to the cylinder-walls, and ports 79 in the end of thepitman provide for the lubrication of its bearing upon the pin 43,sufficient lubricant finding its way past the guide-wings 77 toaccomplish this purpose. An electric igniting device is shown andcomprises a pair of contact-plates 8O 81, rigidly secured in parallelplanes to but insulated, as shown, from a plug 82, adapted to be screwedinto the outer wall of the cylinder 25. A wiping-pin 83, fixed in one ofthe balance-wheels, as 39, passes between the contact-plates 80 81 andcloses the circuit between them. To facilitate this action, each of theplates is `provided with lateral backwardly-turned guide-lugs, as shownat 84 85. plates there are laterally-projecting apertured lugs 86, 87,88, and 89, whereby one plate may be connected by means of wires, asshown, with one of the poles of an electric generator and the other withone of the electrodes or'sparking-points. The electrodes are shown atand 91, and each consists of a carbon pencil incased within a suitablein; sulating-bushing 92, set Within a tubular plug 93, passing throughthe walls of the cylinder 25, the two electrodes being so disposed thattheir points are suiiiciently close to each other so that when theelectric circuit is closed by the contact of the brush-pin 83 with thecontact-plates a spark will pass from one to the other.

The operation of the engine is as follows: A suitable electricgeneratorhaving been connected with one of the contact-plates 80 8l, thelubricant having been placed within the chamber 50a a supply of liquidhydrocarbon in the chamber 66, and the cup 73 having been supplied withsimilar hydrocar- At the base of each of the contact/J' IOO bon, theneedle-valve 74 is retracted, allowing asma-ll quantity of the fuel inthe cup to find its way into the chamber 70, and the crank-shaft havingbeen rotated, by hand or other means, a single turn the valve 6l isopened by the contact of the governing device with the outer end of itsstem, allowing the fuel to enter the combustion-chamber, and there is atthe same time an inward rush Yof air from .the chamber 50a through thepiston-ports and against the valve 6l, Vaporizing a sufficient quantityof the fuel to provide an explosive mixture, and as the piston reachesthe end of its instroke a spark crosses from one electrode to the other,causing an explosion, which is sufcientlystrong to cause a completestroke of the piston and'set the engine in motion. By the time theliquid has been exhausted from the cup 73 the vaporization of the fuelwithin the pipe 67 will be sufficiently rapid to provide for thecontinuous operation of the engine. At each instroke of the piston airis drawn into the chamber 50a through the ports 51a, and at eachoutstroke the air in this chamber is somewhat compressed, and by meansof the passage 7l IIO an equal pressure is maintained within the chamber66, insuring the presence of liquid hydrocarbon in that section of thetube 67 which is inclosed within the exhaust-pipe 59. As the pistonapproaches the end of its outstroke the exhaust-ports 56 are uncovered,allowing the escape of the gases within the combustion-chamber andreducing the pressure therein sufficiently so that the compressed airwithin the chamber will raise the valve 53 and pass into thecombustionchamber with great velocity. The upstanding flange 55 of theplate 54 directs this current of air upwardly toward the induction-port,which is opened as the piston reaches the end of its outstroke. Theinrnshing air expels the residue of the burned gases, so that by thetime the piston has advanced on its instroke so as to cover the ports 56there remains within the combustion-chamber only the new charge of airand hydrocarbon vapor, and by reason of the direction taken by theair-current as it enters this chamber these two have become thoroughlyintermixed. As the piston continues to advance on its instroke thecontents ofthe combustion-chamber are compressed, and both the valve 53and the valve (il are thereby seated, the spring coperating to close theinduction-port. The brush 83 is so located upon the wheel 3S that theelectric circuit is closed at the end of the instroke of the piston,andan explosion is thereby caused, and the engine commences a new cycle.The deflectingwings 77 upon the pitman cause the air as it passes fromthe chamber 50 to the combustion-chamber to sweep the walls of thepiston, thereby sufliciently cooling the latter, so that there is notendency to premature explosions. By the use of fixed electrodes thespark may be developed close to the cylinder-walls, and as theelectrodes project but a short distance beyond these walls they aresufiiciently cooled by the water within the jacket. I prefer to useround carbons and to point them, so that if they become incrusted theymay be easily pushed inwardly until their beveled faces come intocontact and then being rotated will abrade and clean each other. Leakageabout the crank-shaft is guarded against bythe use of linings 94 for thejournal-boxes in spool form, which not only are so constructed as to titsnugly within the boxes and around the crank-shaft, but the inner endsof which form bearings for the radial faces of the crank. The pressuredeveloped within the chamber 50 is not such as to render it necessary toprovide a stuingbox, and the construction described not only enables meto obtain close -fitting joints without an excess of friction, butthejoints,which might form a passage for the escape of air, are verylong, and the presence ot' the lubricant within the chamber provides apacking for them.

I have not deemed it necessary to show water connections for thecooling-jacket, as this feature of the engine is the same as is almostuniversally practiced.

lf desired, a cup 95 may be located at the lower end of the pipe 67,within which there may be placed a combustible iiuid which upon beingignited will heat the tube and vaporize some of the fuel for service instarting the engine.

The diameter of the piston exceeds the length of its stroke. As a resulta great area of piston-face is exposed to the pressure developed withinthe cylinder, while the area of cylinder-wall surface exposed to theheat of the burning vapors is correspondingly reduced.

I claim as my inventionl. In a reciprocating gas-engine, in combination,a trunk having at one end a powercylinder, at its opposite end afuel-reservoir and an intermediate compression-chamber, a-

piston adapted to reciprocate within the cylinder, having a passageconnecting the compression-chamber with the cylinder, a valve for thepassage, a plate for retaining the valve in place having a tubularextension, a valvegoverned induction -port arranged axially with thetubular extension, a valve-closed passage connecting thecompression-chamber with the reservoir, and a connection between thereservoir and the cylinder.

2. In a reciprocating gas-engine, in combination, a trunk having at oneend a powercylinder, at its opposite end a fuel-reservoir and anintermediate compression-chamber, a piston adapted to reciprocate withinthe cylinder, a valve-closed passage connecting the compression-chamberwith the reservoir, an exhaust-tube, an oil-pipe leading from thereservoir through the exhaust-tube, and a vapor-reservoir communicatingwith the oil-pipe and the cylinder.

3. In a gas-engine, in combination, a cylinder havinga valve-closedfuel-induction port, a compression-chamber inclosing the enginecrank andhaving an induction-port, a piston reciprocating in the cylinder andhaving a passage opening from the compression-chamber to the cylinder, avalve carried by the piston, and a tube arranged axially to thefuel-induction port forming a continuation of the said passage.

4. In a gas-engine, a cylinder having an induction-port inits head,acompression-chamber inclosing the engine-crank and having aninduction-port, a piston reciprocating in the cylinder and havin gacheck-valve-closed passage opening from the compression-chamber to thecylinder, and a plate secured to the piston for retaining thecheck-valve in place and having a tubular flange forming a continuationof such passage for directing aircurrents passing therethrough againstthe head of the cylinder.

5. In a gas-engine, in combination, a cylinder having a valve-closedfuel-induction port, a compression-chamber inclosing the engine- IOO IIO

crank and having an induction-port, a piston reciprocating in thecylinder and having a passage opening from the compression-chainber tothe cylinder, a valve carried by the piston, and a plate securedl to thepiston for 'retaining the valve in place and having a tubular flangearranged axially to the fuel-induction port and forming a continuationof the said passage.

6; In a gas-engine, acylinder, a compression-chamber inclosing theengine-crank and having an. induction-port, a piston reciproeating inthe cylinder and Yhaving a checkvalve-closedpassage opening from thecompression-chamber to the cylinder, a pitman pivotally secured to thepiston within its body, and lateral deflecting-wings near the piston endof the pitman.

7. In a gas-engine, in combination, a cylinder, a pistonA reciprocatingtherein, a compression-chamber at the end ot' the cylinder and having aninduction-port, the piston having an annular series of ports through itshead, an annular valve for covering such ports and opening toward thecylinder, and a retaining-plate for the valve having a tubular flangeforming a continuation of the passage.

8. In a gas-engine, in combination, a cylinder having a fuel-inductionport in its head, an inwardly-opening valve for such port having atubular stein, a reciprocating piston, a

rodiixed to the piston and extending'througli` the valve-stem and bein gprovided With'nieans for engaging such stem to open the Valve as thepiston approaches the limit of its outstroke.

9. In a gas-engine, in combination, a cylinder having a fuel-inductionport in its head, an inWardly-openin g valve for such port having atubular stem, a stufng-box fitted to such stein, a reciprocating piston,a rod fixed to the piston and extending through the Valve; stem andbeing provided with means for engaging such stem to open the valvek asthe piston approaches the limit of its outstroke.

10. In a gas-engine, in combination, acylinder, a tubular valve-casingset through the head thereof and having a lateral inductionport andVconstituting the induction-port of'`

